I’m sure this topic has been discussed here ad nauseum before. I did some searches as well and found related posts so I apologize for repeating it.

I ride my ‘63 R69S about once or twice a week. Normally about 10-20 miles a trip. In the past few months I started noticing some fluid leak below it. It was never much. I thought at first it was oil. Before every ride I check the oil level and it’s always the same and I could never find the source of the leak. (My apartment garage is not very bright). Well yesterday the leak was bigger and I saw it was possibly coming from the petcock. Please see pic below.

Is this common? Should I buy a new one or a rebuilding kit will suffice? How hard is it? I’m not the most mechanically inclined person.

That's a Karcoma petcock which most find to be a lot more reliable than the original Everbest. There does appear to be evidence of vanished fuel on and around the tap. That said, you need to determine where it's coming from first. Is the petcock at all loose? Perhaps it just needs to be snugged up. Are your braided fuel hoses cracked and brittle with age?

I'd grab a can of carb cleaner and give the tap a spray and a wipe. That'll get all that yellowish varnished fuel off then turn on the tap and find where it's leaking. It wouldn't hurt to drain your tank and remove the tap altogether, clean it thoroughly with carb cleaner and reinstall. But before you go to the trouble try those first recommendations.

I've never needed to rebuild a Karcoma but I've dealt with a few leaky Everbests which don't really take well to rebuilding. I've never seen an available rebuild kit for the karcoma but that doesn't mean one doesn't exist.

After looking at your photo again I'd say it's safe to rule out the fuel lines. With fuel varnish all the way at the top of the tap I'd bet it's loose or the gasket at the threaded tank outlet is no longer creating a good seal. Try lightly snugging up the tap. From turning it on and off over the years the back and forth could be slowly loosening it.

Hi
I have 2 of these taps fitted to my 1961 R69S with a 33 Litre Heinrich tank . They have been on for about 5 years with no leaks or any other problems . Suggest you order a new one from Vech . You will need to advise the thread size .That is where i bought my taps ( petcocks ) from . Regards

I would do what Slash suggests. Worst case, you need a new seal ring (petcock to tank) and the new rubber disc for inside the petcock. All in all most likely less then 5 bucks. Rebuilding a Karcoma is a walk in the park ... veeery different to rebuilding the Everbest torbedos. Takes less than 10min.
I would use the extra cash (difference to a new petcock) to buy some gas for a nice ride. My 2 cents

Thank you Slash2 and all other commenters. I did look around a little more and it’s your assumption is correct. It’s coming from the top. Probably a gasket failed. I will order the rebuild kit from Vech today. Glad to know I have an Karcoma petcock. I’ll keep you updated after I do the rebuild.

I rebuilt the petcock this weekend after receiving the parts from Vech. Good news is the petcock is now bone dry. Bad news is there are 3 new leaks.
1) There seems to be an oil leak coming from the oil pan gasket on the bottom - I ordered a new gasket to replace it
2) There is a gas leak from the left side carburator - I think I need to adjust the nut there (please see video link below)https://youtu.be/lD5926gSi40
3) There was a small puddle of oil just below the transmission. I couldn't see where this was coming from. Any suggestions are appreciated.

@1: welcome in the club. Once new gasket is installed, don't torque the bolts down too much. The tin oil pan doesn't like this at all. Start easy and retorque once you see fit. Put some veeeeery little sealant on the threads of the bolts. The bolt holes actually go through the material and it could leak from there. There are enforcement rings available which help to avoid the tin pan to de-form ... would be a good idea. Even better is you replace the original pan with an aftermarket aluminium pan ... no leaks anymore. However, if you only drive short distances, the engine will take longer to warm up.
@2: I can't see the video. Left carb leaks when you put the bike on the sidestand ... that is normal. If it also leaks on center stand, use some cigarette ashes and match the needle tip to the top where the gas line goes into the carb. I know my english is a bit bumpy but I hope you understand what I mean
@3: Not good. Check where it is coming from. If you use tranny oil for the transmission and motor oil for the motor, its easy to figure out where the oil is coming from. They will smell differently ... at least that's what I think. Once you know where the oil is coming from, than you know which seal ring you need to replace.

You can get an oil-tight pan by using Permatex Ultra-Gray sealant on the gasket and the bolt threads, as was mentioned. Left carb will leak out the vent hole in the mixture screw if gas is left on and bike is on side stand. Both carbs may seep a bit at the jet plugs - very hard to prevent that. Try using pipe thread sealant on those if they drip.

The oil on the 'shelf' could be the rear main seal leaking, or the front transmission seal, as was also mentioned. A bit of work to fix those. Trans has to be removed for either job.

Update
The oil pan leak was fixed with a silicone type gasket instead of the cork one. It’s supposed to last forever and can even be reused.
The transmission leak was coming from the shifter itself. We took it apart and sure enough the rubber ring gasket inside had been completely petrified. It was replaced and the leak stopped. It just left me wondering how many other rubber seals are petrified and should be replaced. Anyway thank you all for the help.

I'll bet that if you took a poll, more than half of the /2 owners would report a small seepage of oil onto the shelf. Mine has done that for most of the half century it has been in the family. I just wipe it out with a paper towel after each ride and add a little oil to the gearbox maybe once or twice a year. It's like the dripping from the carburetor when the petcock is open and the bike is on the center stand. Call it character.